Storage devices mounted on a payload board can be added to computer systems to increase or augment storage capacity. Storage devices generally communicate to external devices using a storage protocol, such as SCSI, IDE/ATA, and the like. In order to transmit data stored on storage devices, data is generally communicated from the storage devices to a computer system using primarily a parallel multi-drop bus network architecture, such as Peripheral Component Interconnect (PCI) or VERSAmodule Eurocard (VMEbus). A multi-drop parallel bus architecture has the disadvantage that it can only be used to support one instantaneous communication between modules in a computer system or network. Some applications have requirements for simultaneous high bandwidth transfers between storage devices and other devices, such as processors located elsewhere in the embedded computing environment, which cannot be handled by the multi-drop parallel bus architecture.
In the prior art, 6U form factor cards are common. The 3U form factor offers an advantage for applications where physical space is at a premium. The 9U form factor offers an advantage of placing more computing features on a given card. Prior art 3U and 9U form factor expansion cards interface with a backplane using parallel multi-drop networks. This has the disadvantage of being slow and cumbersome for network expansion.
Accordingly, there is a significant need for an apparatus and method that overcomes the deficiencies of the prior art outlined above.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawing have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to each other. Further, where considered appropriate, reference numerals have been repeated among the Figures to indicate corresponding elements.